A host attachment is a grouping of one or more host ports. You can use host attachments to configure multiple ports at the same time, in the same way. For example, you could have three pSeries hosts with four host ports each. The first host, pSeries1, has no specific attachment groupings, so each port is defined as an attachment. The pSeries2 has two host attachments, with two ports in each attachment, and pSeries3 has one host attachment with four ports grouped in the one attachment.
A host attachment identifier is automatically generated based on the host name, host type, port type, number of ports in the attachment, and order of creation.